HEIC0602: FOR RELEASE 12:00 (CET)/6:00 AM EST 28 February, 2006
http://www.spacetelescope.org/news/html/heic0602.html
Photo release:
Largest ever Hubble galaxy portrait — stunning HD image of Pinwheel
Galaxy
28-February-2006 This new Hubble image reveals the gigantic Pinwheel
galaxy, one of the best known examples of “grand design spirals”, and
its supergiant star-forming regions in unprecedented detail. The image
is the largest and most detailed photo of a spiral galaxy ever released
from Hubble.
Giant galaxies weren’t assembled in a day. Neither was this Hubble
Space Telescope image of the face-on spiral galaxy Messier 101 (the
Pinwheel Galaxy). It is the largest and most detailed photo of a spiral
galaxy beyond the Milky Way that has ever been publicly released from
Hubble. The galaxy’s portrait is actually composed from 51 individual
Hubble exposures, in addition to elements from images from ground-based
photos. The final composite image measures a whopping 16,000 by 12,000
pixels.
The Hubble observations that went into assembling this image composite
were retrieved from the Hubble archive and were originally acquired for
a range of Hubble projects: determining the expansion rate of the
universe; studying the formation of star clusters in giant starbirth
regions; finding the stars responsible for intense X-ray emission and
discovering blue supergiant stars. As an example of the many treasures
hiding in this immense image, a group led by K.D. Kuntz (Johns Hopkins
University and NASA) recently catalogued nearly 3000 previously
undetected star clusters in it.
The giant spiral disk of stars, dust and gas is 170,000 light-years
across or nearly twice the diameter of our Milky Way. The galaxy is
estimated to contain at least one trillion stars. Approximately 100
billion of these stars alone might be like our Sun in terms of
temperature and lifetime. Hubble’s high resolution reveals millions of
the galaxy’s individual stars in this image.
The Pinwheel’s spiral arms are sprinkled with large regions of star-
forming nebulae. These nebulae are areas of intense star formation
within molecular hydrogen clouds. Brilliant young clusters of sizzling
newborn blue stars trace out the spiral arms. The disk of the galaxy is
so thin that Hubble easily sees many more distant galaxies lying behind
the foreground galaxy.
The Pinwheel Galaxy lies in the northern circumpolar constellation,
Ursa Major (The Great Bear) at a distance of 25 million light-years
from Earth. We are seeing the galaxy from Earth today as it was at the
beginning of Earth's Miocene Period when mammals flourished and the
Mastodon first appeared on Earth. The galaxy fills an area on the sky
of one-fifth the area of the full moon.
The newly composed image was assembled from archived Hubble images
taken with the Advanced Camera for Surveys and the Wide Field and
Planetary Camera 2 over nearly 10 years: in March 1994, September 1994,
June 1999, November 2002 and January 2003. The Hubble exposures have
been superimposed onto ground-based images, visible at the edge of the
image, taken at the Canada-France-Hawaii Telescope in Hawaii, and at
the 0.9-meter telescope at Kitt Peak National Observatory, part of the
National Optical Astronomy Observatory in Arizona. Exposures taken
through a blue filter are shown in blue, through a green filter in
green and through a red filter in red.
# # #
Notes for editors
The Hubble Space Telescope is a project of international cooperation
between ESA and NASA.
Image credit: European Space Agency & NASA
Acknowledgements:
Project Investigators for the original Hubble data: K.D. Kuntz (GSFC),
F. Bresolin (University of Hawaii), J. Trauger (JPL), J. Mould (NOAO),
and Y.-H. Chu (University of Illinois, Urbana)
Image processing: Davide de Martin (www.skyfactory.org)
CFHT image: Canada-France-Hawaii Telescope/J.-C. Cuillandre/Coelum
NOAO image: George Jacoby, Bruce Bohannan, Mark Hanna/NOAO/AURA/NSF
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For more information, please contact:
Sřren Larsen
ESA/Space Telescope European Coordinating Facility
European Southern Observatory, Garching, Germany
Tel: +49-(0)89-3200-6576
E-mail: slarsen@eso.org
K.D. Kuntz
Johns Hopkins University/NASA Goddard Space Flight Center
Tel: +1-301-286-1201/+1-410-366-4236
E-mail: kuntz@milkyway.gsfc.nasa.gov
Lars Lindberg Christensen
Hubble/ESA, Garching, Germany
Tel: +49-(0)89-3200-6306
Cellular: +49-(0)173-3872-621
E-mail: lars@eso.org
Ray Villard
Space Telescope Science Institute, Baltimore, USA
Tel: +1-410-338-4514
villard@stsci.edu